package day240522.Interface;

public interface Y  {
        void teach();
        void play();
        default void Xxx(){
            System.out.println("Y.xxx");
        }
        static void Zzz(){
            System.out.println("Y.zzz");
        }
    }
interface YPlusPlus extends Y {
    void sing();
}

class Y4 implements YPlusPlus {

    @Override
    public void sing() {

    }

    @Override
    public void teach() {

    }

    @Override
    public void play() {

    }

    class Y1 implements Y {
        @Override
        public void teach() {
            System.out.println("Y1.teach");
        }

        @Override
        public void play() {

        }
    }

    class Y2 implements Y {
        @Override
        public void teach() {
            System.out.println("Y2.teach");
        }

        @Override
        public void play() {

        }
    }

    class Y3 implements Y {
        @Override
        public void teach() {

        }

        @Override
        public void play() {

        }

    }
class Test3{
    public static void main(String[] args) {
        Y.Zzz();
//        Y3.Zzz();
    }
}}
